The synthesis of monomeric and dimeric porphyrins is planned for use as affinity ligands and as models to study the redox chemistry of heme proteins. In addition the qualitation and quantitation of porphyrins from porphyric sources is being pursued by the use of high pressure liquid chromatography. BIBLIOGRAPHIC REFERENCES: J.B. Paine and D. Dolphin. The Use of Ferric Ammonium Nitrate in Pyrrole Chemistry. Canad. J. Chem., 54, 411, 1976. R.H. Abeles and D. Dolphin. The Vitamin B12 Coenzyme, Accounts Chem. Research, 9, 114, 1976.